Reissued



J. E. NORWOOD.

PISTON RING.

APPLICATION FILED AUG.I4. 191a.

Patented May 20, 1919.

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To all whom it may concern: from each of the grooves 4 and 8 are a num-Be it known that I, JOHN E. Noawoon, a citizen of the United States,residin at Baltimore, in the State of Maryland, ave invented certain newand useful Improvements in Piston-Rings, of which the followis aspecification.

his invention relates to im rovements in piston rings and has for its obect to provide a supplemental ring which cooperates with the plston ringor rings to prevent the oil from workin around and over the piston ringsto the ri the gas in the firing chamber from passing around the pistonring, and also to rovide means to allow the oil that works -un er andback of the piston rings to drop back into the crank case.

The invention consists of the novel construction and arrangement of theparts and combination of parts hereinafter more fully set forth in thefollowing specification and pointed out in detail in the appendedclaims.

In the accompanying drawing Figure 1 is a vertic section of .a cylinder,the iston therein having my invention applied thereto.

Fig. 2 is an enlarged section of a portion of the cylinder and piston.

Fig. 3 is a modification showing the piston ring in two sections.

Referring to the accompanying drawings, form' part of thisspecification, and m which 'ke reference numerals designate like partsthroughout the several views, 1 designates a cylinder and 2 the piston,the latter being operated in the cylinder through the medium of the rod3 leadingto the crankshaft (not shown) of the engine. The said iston isprovided with annular rooves 4 into which the piston rings 5 fit. aidrings 5 each have overlap ing ends 6 and annular recesses 7 one sur aceof which is cut at ri ht angles to the face of the ring and the ot ersurface is inclined so that when the piston moves in one direction thestraight surface will force the oil into the recess and when the pistonmoves in the opposite direction the inclined surface of the recess 7will cause the oil to spread on the side of the cylinder. The innersurface of the grooves 4 is provided with a smaller annular vs 8 intoeach of which latter a supplemental ring 9 is. fitted; said rings 9 avetheir outer surfaces impinging against, the inner surface of the pistonrings. Leading chamber, and to prevent.

ber of a rtures 10 and 11, respectively, passing t rough the side of theiston to allow the oil to drop back into e crank case. In practice whenthe 'ston 2 moves down the rin 5 are against t e top of their grooveswhic forces the oil under and back of the piston rings 5. until itstrikes the supplemental rings 9 which latter will prevent theoilworking over the piston rings when the piston is forced up again, asin the case with the piston rings in resent use. When the oil strikesthe supp emental rings 9 it will pass through the apertures 10 to thecrankcase, and any oil which might work back of the supplemental rings 9will drain through the apertures 11 and also drop back into the crankcase.

In Fig. 3 I have shown a modificationof the piston ring 12, the samebeing made in two sections.

While I have shown and described a piston ring with a groove in itsouter surface, a

and also a piston I'll-1:5 formed of two sections, any ,ot er desi formof piston rin may be employed with the supplemen It will be seen that bythe use of m present invention the piston will be wel oiled, but that nooil can pass by the piston rings and into the firing chamber as thesupplemental rings 9 fit closely in the grooves 8 and at all times impina inst the iston rings, and are not a ecte by centrifugal force orvacuum, and the oil that works under the piston rings will strike the suplemental rings 9 and pass off through t apertures to the crank case,and any oil that may work back of said supplemental rin 9 will drainthrou h the apertures 11 an also dro back into t e crankcase.

Having us described my invention, what I claim is:

1. The combination of a piston havin an annular groove in its outersurface rovided with apertures leading to the insi e of the 7' pistonand a smaller annular groove at the ack of the first named annulargroove and also provided with apertures leadi from said smaller grooveto the inside of t e piston, a-piston ring fitted in 'the saidfirstnamed annular groove, and a suupplemental ring fitted in saidsmaller an ar groove an against the piston rin 2. The com ination of apiston annular grooves in its outer surface m .8 LOOMO' provided withapertures leadi to the int angles to the face of the rings and the sideof the piston and a sum or annular 0 er surface is inclined,andaaupplemental groove back of each of said first named anring fittedin each of said smaller annular nular ves and also provided withapergrooves and impinging against the piston 5 tures eading to theinside of the piston, a a t Elston ring in each of saidfirst named annuntestimony whereof I aflix my signature.

grooves and each having a inite a r .outer face one surface of which iscut at JOHN E. NORWOOD.

